Sparking device for gas-engines



No. 753,511. PATENTBD MAR. 1, 1904.. G. J. MURDUCK.-

SPARKING'DEVIGE FOB. GAS ENGINES. APPLICATION FILED MAR.21, 1903. N0 MODEL. 3 SHEETS-SHEET 1.

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f G. J. MURDooK.

SPARKING DEVICE FOR GAS ENGINES.

' APPLICATION FILED MAR. 21, 1903. Y N9 MODEL. 3 SHEETS-SHEET 2.'

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PATENTBD MAR. 1, 1904.

G. J.V MURDUGK.. SPARKING DEVICE PoR GASBNGINES.

APPLIOATIGN FILED MAE. 21, 1903.

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Patented Maren 1, 1904.

UNrrEDy STATES .PATENT VOvinos.

GEORGE J. MURDCK, OF NEWARK, NEI/V JERSEY.

SPARKING DEVICE FOR GAS-ENGINES.

SPECIFICATION forming part of Letters Patent No. 753,511, dated March 1, 1904. Original application led February 11, 1903, Serial No. 142,902. Divided and this application led March 21, 1903. Serial .Engines, of which the following is a specification.

My'invention relates to gas-engines of the kind in which an explosive charge is fired by -means of electric sparks produced in the combustion-chamber of the engine by making and breaking an electric 'circuit at proper intervals. v

In carrying out my invention I provide the .sparking electrodes Within the combustionchamber oi' the engine with multiple contacts constructed, arranged, and operated in animproved Way, one of the electrodes-being pref- -erably in the form of a toothed wheel secured to the inner end of a shaft, the outer end of which carries another toothed wheel, which is actuated from the crank-shaft of the engine. In order to prevent short-circuiting across the insulation in the combustion or sparking chamber, I apply to the inner end of the shaft a bell or cup shaped shield, into which the explosive mixture is forced during the first compression stroke oi' the engine. The mixture within the cup having been burned upon the first explosion of the engine', the products of combustion or inert gases remain within the cup or shield and exclude the explosive mixture of subsequent charges admitted to the engine, and thereby prevent the deposit of carbon upon the surface of the insulation separating the twosides of the spark-circuit within the combustion or sparking chamber. This feature of the invention is not dependent upon the special style of sparking devices or electrodes. The details of construction of the mechanism thus brieiiy outlined are hereinafter fully explained.

The preferred ways of embodying my improvements are shown in the accompanying drawings, in whichn Figure 1 shows a vertical central section through the combustion-chamber of the engine and through the igniting devices. Fig. 2 shows a vertical central section through the `application above referred to.

(No model.)

combustion-chamber on the line 2 2 of Fig. 1

with the igniting devices in elevation. Fig. 3 is a detail view, on an enlarged scale, of a sleeve or spool carrying mica disks forming part of the insulation around the toothedwheel shaft. Fig. 3 is a view of the lower end of the spool. Fig. 4 is a detail view in section on the line 4 4. of lFig. 2., illustrating the manner in which the outer toothed Wheel is operated. Fig. 5 shows a transverse section on the line 5 5 of Fig. 2. Fig. 6 is a view similar to Fig. 5, one of the members oi' the igniting devices, however, being diderently constructed. Fig. 7 isa diagram oi' the igniter circuit and illustrates the manner in which a thermostat is employed to open this circuit when the heat oi' the engine becomes excessive. Fig. 8 is a detail sectional view showing an ordinary form of electric igniterplug with the bell or shield applied to protect the insulation from deposit of carbon, the sparking occurring at the edge of the bell.

In my application for patent, Serial No.

142,902, iiled February l1, .1903, I have shown and described a complete lgas-engine capable of performing all the necessary operations,

and inthat application I have shown and de-V scribed igniting devices similar to those herein shown, described, and claimed, this application being a division oi' that before mentioned.

A indicates a casting within which the combustion -chamber' isV formed, to which latter the explosive mixture is admitted through the opening c in the manner described in my The casting connects with the engine-cylinder through the opening a and the exhaust takes place through the Opening a2. y The opening a3 in line with the opening c2 is closed by means of a plug ai.-

`The sparking or igniting devices are located within the combustion-chamber in line with the passage c', and between the openings a2 a3 there is-an opening a5, which may be closed by a plug. This latter opening is also in line with the igniting devices, and access tor them maybe obtained through said opening.

Referring iirst to the construction illustrated particularly in Fig. 6, it will be seen that a ringer B is pivoted to lugs Z2', attached to a nut b2 on the end of a sleeve 6.3, which passes IOO through the opening a on one side of the casting A. This finger is adapted to engage with a toothed wheel C, operated in the manner hereinafter described. It is curved or segmental in outline, and as it wears away and is adjusted inward its inner end will always maintain a proper relation with the toothed wheel C. As the end of the finger wears away a'rounded surface is produced by sparks, which will allow the finger to move freely without becoming locked with the toothed wheel C. The sleeve b3 has an exterior screwthread and receives a nut b4, the nuts b2 and b4 serving to clamp the sleeve in place on the casting A in the manner illustrated in Fig. 6. Within the sleeve is arranged a sliding block b5, which is pressed inward by means of a spring the outer end of which bears against a cap 57, adjustably attached to the sleeve b3. This sleeve carries a rod bs, which extends through the sleeve 3 and is adapted yto slide back and forth therein. The inner end of this rod is bent downward and engages the pivoted finger B. By the arrangement shown when the nger B is moved on vits pivot the rod 68 may be moved outward against the force of the spring be and inward by means of the spring when the latter is released. The finger B constitutes one electrode, which I call the ground contact of the igniter-circuit. It will be observed that most of the parts are located outside of the combustion-chamber,

the spring and all the adjusting devices being so arranged. The inward movement of the finger is limited by the inward movement of the block b5, and by adjusting the block on the outer end of the rod 728 this movement may be regulated. The sleeve b3 may also be adjusted radially toward and from the toothed wheel C to control the .engagement of the {in ger with said wheel. I may lill thecap b* with powdered graphite to lubricate the parts. No packing is required, and yet the connections are all gas-tight. The other electrode is the wheel C, before referred to. This Wheel is preferably a starwheel; but an ordinary toothed wheel will answer the same purpose. It is adapted to be revolved to engage and to break connection at proper times with the finger B, and it is se cured to the lower end of a vertical shaft C', which extends up through the top'of the casting A and carries at its upper end a toothed wheel C2, which is operated step-by-step by devices carried by the upper rear end of a lever E, which, as described in my application for patent above mentioned, is operated from the crank-shaft of the engine. The drawings show the wheel C2 as being provided with twelve teeth, 'while the wheel C is formed with six teeth. By this arrangement the igniting devices are operated to produce a spark after each two actuations of the wheel C2, and asa plurality of teeth are employed on the wheel C the life of this wheel is made much longer electrode.

than would be the case if only one tooth were used.

It is not necessary of course to insulate the ground contact from the frame of the engine; but it is vimportant to provide efficient means for'maintaining the insulation of the other Diiiiculties have heretofore been encountered, the most serious one of which is short-circuiting across the insulation by deposit of carbon, resulting from the exploded gases. I have devised an efficient remedy for this difficulty and effective devices for preserving the insulation that Vare applicable to electric igniters'generally and not confined in their usefulness to the particular organizations herein disclosed. The opening in the top of the castingv A is closed by means of a screwplug C3, and to this plug all parts of one member of the igniting devices are attached. The plug C3 is formed with a sleeve c, which extends down into the combustion-chamber around the shaft C. Within this sleeve is located insulating material c', preferably consisting of a vertical series of mica disks carried by a metal spool e2. The spool is fianged at its upper end c3 and is provided at its lower end with a nut e4, the disks being held securely between the flange and nut. If desired, a washer 0X may be interposed between the nut and the mica disks. The nut 04 is of smaller diameter than the sleeve c, being out of contact therewith, while the disks it thesleeve closely. The flange c3 is arranged slightly above the bottom of the recess cl3 in the upper portion of the plug C3 and is of less diameter than this recess, so that its edges do not come in contact with the walls thereof. A few of the'mica disks at the top of the spool areof larger diameter than the others and rest on the bottom wall of the recess cl3 and insulate the iiange therefrom. In this way t-he spool is completely insulated from the plug. The shaft C near its lower end is shouldered at c and receives a cup, bell, or shield Cf, which is held on the shaft against the shoulder'by the wheel C and the nut c, The cup extends upwardly from the lower end of the shaft and surrounds the sleeve c, leaving an annular space c5, which becomes Jfilled with spent gases or products of the first explosion that thereafter prevent the admission to the cup of explosive mixture of subsequent charges, thereby preventing deposition of carbon across the insulation between the nut c4 and sleeve c and rendering impossible short circuit at this point from the shaft C through the nut o4 to the sleeve c and thence to the frame of the engine. By using the cup C4 this deposit of carbon to an injurious extent is entirely prevented, and the cup also acts to prevent to a material extent overheating the insulation. In gasolene-engines especially and to some eX- tent in gas-engines not only does soot gradually accumulate on the electrodes, but small pieces of carbon are from time to time broken IOO -ing on the electrode.

"The arrangement of the cup is such Vthat these j-smail pieces of carbon are prevented lfrom lodg- It will be observed that fthe cup opens outward-e'. e.. WaY from the YYlcombustion-chamber.

Its lower end facing the combustion-chamber is closed, and its upgland, as well as from the washer.

- w asher.

'fpe'r edge is close to the wall of the chamber, and as the cup revolves any pieces of carbon that might tend to lodge on it are shakenof'f. The recessed upper end of the plug C3 is filled lwith asbestos c1, held in place by a gland C5,

'above which is located a recessed washer o8, y,i'r'isulated from another washer c above it, upon which bears a spring 01, surrounding the p "shaft C' and bearing against the under side of a collar c thereon. This spring tends to force ythe shaft upward, thus avoiding any contact or packing at the lower end of the cylinder, where it would be subject to heat, and also -providing suflicient friction to prevent the wheel C2 from turning or moving except when positively moved by the lever E. The upper end of the shaft C is connected with a frame F, attached to the plug C3; but the shaft is insulated from the frame F in the manner indicated at f2. It will be observed that the asbestos c1 extends up through the gland and also' through the washer cs, thus surrounding .the shaft C and completely insulating it from the This precise arrangement, however, is not essential, as the insulation is maintained properly by reason of the fact that the shaft cannot make contact with the gland, as it passes through a comparatively large opening therein, and the Awasher is held concentric on the gland by the boss on the upper end of the latter, which fits a corresponding recess in the bottom of the The asbestos, therefore, primarily serves as apacking to prevent products of combustion from being forced out along the shaft. The shaft C is bored axially, as indicated at f, the passage-in the shaft extending downward in the manner indicated to permit lubricating material to be carried to the point where it is needed. The top of the passage fv is closed by a boltf'. o

The lever E is formed with a slot G, in which is adjustably mounted a block G', of .insulating material. This block may be adjusted by means of athumb-screw Gand the amount of adjustment to obtain the required 'lead may be read by means of an index G3.

Tothis block is attached a pawl X, adapted to engage with the wheel C2 in the manner indicated in Fig. 4. As described in my beforementioned application, the rearend of the lever E is given a back-and-forth and up-anddown movement, resulting in an elliptical movement which gives to the pawl X an elliptical movement, (indicated by dotted lines in Fig. 1.) As the rear end of the lever E is of the engine-shaft, and two impulses must be given to the wheel C2 before the wheel C can be operated to break the circuit and produce a spark vwithin the combustion-chamber.

The electric circuit of the igniting devices is indicated in Fig. 7; VThe battery X is connected on one side with a switch X3, which.

latter is connected with a sparking coil X2, in

turn connected through a thermostat Y with a binding-post Xi, which is electrically conneted with the pawl X. The other pole of the battery may be connected to ground. In the diagram it is shown as being connected by wire with binding-post P of the ground contact M. The pawl X makes contact with the wheel C2 and through the wheel C2, shaft C, and wheel C electrical connection is made with the, ground contact. While the pawl X engages each tooth of thewheel C2, the electric circuit is made and broken every other time that the pawl and wheel thus engage, be-

cause the wheel C has only half as many teeth as the wheel C2. The arrangement is such that no sparking occurs at the wheel C2, because when the pawl X breaks connection with the wheel C2 the circuit is open at the wheei C and contact B or M. In Fig. 6 the end of the Vcontact B is shown as being arranged between two of the teeth of the wheel C, having just passed the tooth Z2 and produced a spark. When the wheel C2 is moved one step by the action of the pawl X on one of its teeth, the wheel C will be moved until the next tooth 51 is brought close to the end of the contact B, but not into connection with it. The next movement given to the wheel C2 by the pawl X will cause the wheel C to move in such manner as to cause the contact B to wipe across the tooth b1, producing a spark and then assuming a position between the tooth 51 and the tooth bu similar to the relative position of the teeth and contact shown in Fig. 6. The other teeth Von the wheel C operate in connection with the contact B ina similar way. It will now be vunderstood that the circuit is both made and from the' battery and is only connected therewith during the time that the pawl X engages the wheei C2, at which time the wheel C is in engagement with the grounded electrode.

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. but preferably consists of two strips y y of Accidents sometimes occur in gas-engines by reason of the fact that the circulation of water is stopped when the engineer forgets to turn on the water or the water falls below the proper level in the stand-pipe. When this occurs, the excessive heat causes'the oil to carbonize and the piston to cut the cylinder. To guard against accidents of this kind, I employ a thermostat which is adapted to open and close the circuit of the igniter and stop the engine by suspending the operation of the igniting devices when the heat of the engine rises to a predetermined degree. mostat Y is attached to the rear end of the cylinder. It may be of any suitable construction,

dissimilar metal, such as brass and soft steel. The brass strip is preferably placed next to the cylinder, as the brass expands more than heat occurs the lupper end ofl the thermostat will tip outward,l andthus break the circuit at. the contacts g3 y, and there fore the operation1 of the igniting devices will be suspended, and as no .explosion occurs the enginey will come to rest and will remain atrest until the circulation of water has commenced again and the heat of the cylinder falls to the predetermined degree. p i ,Y

Instead of employing a contact-finger B in connection with the starwheel I prefer to employ a ground-contact in the If ormof a toothed wheel M. .By so doing. m'nltiple contacts are' alorded kon bothifmembers of the igniting devices and no adjustment is required. This modification is kshown in Figs. 2 and 5. The wheel M is secured to a shaft M', which extends through a vertical opening in the casting A. At its upper vend thesliaftfMisl formed with a flange or collar m', against the outside of which bears a spring N, arranged within a cap N,.wh1ch engages a threaded boss n of the casting. The lower end of the shaftv M in proper vertical position, but prevent- ,t ing it from turning except when positively actuated by the star-wheel C. rlhis wheel M may be connected to the shaft M byafeather- The ther- )lormally4 the circuit is,v closed through the thermostat; butfwhen excessive and-groove connection. The shaft M may be removed by withdrawing the cap N', while the wheel may be taken out through the opening a5. In other respects the construction of the apparatus shown in Figs. 2 and 5 is similar to that shown in Figs. 1 and 6. In the special construction shown the wheel M has seventeen teeth and the wheel C has six. In Fig. 5 the two members C and M are so related that the teeth 0 on the star-wheel has just broken 4connection with the tooth m on thewheel M, thereby producing aspark. The next movement given to the wheel C2 will vcause the tooth 0 on the wheel C to move almost into contact with the tooth m on the wheel M, while the next movement of the gether the teeth 0 and m will separate, thus breaking .theI circuit, with a resulting spark.

It will be observed that when the pawl X iirst i Vengages the wheel C2 (the parts'being argro 'I have described two modications of my j Il',

invention; but the mechanism may be still further modied Without departing from the novel features involved in the constructions illustrated. The igniting devices instead of being applied to anv outside or supplemental combustion chamber, as shown, may be applied to the rear end of a cylinder, as is some-f times done, and the devices for automatically stopping the engine by opening the ignitingcircuitmay be applied to explosive-engines of various types.

Fig. 8 shows an ordinary igniter-plug, combining an electrode or terminal l, surrounded by insulation 2, contained in a plug 3, screwing into the wall 4. rlhe cup, bell, or shield C4 is attached to electrode 1 and extends around the insulation 2. As shown, sparking is designed to occur between aprojection 5 on the edge of the cup and one, 6, on the end of plug 3. The igniter circuit may be arranged, equipped, and broken in any usual orsuitable Way- I claim as my invention- 1. The combination of combustion chamber, two electrodes therein, electrical 'connections therefor, and means for giving a stepby-step movement to one of said electrodes and for causing it to both make and break the circuit during each alternate movement on y.

2. The combination of a combustion-chamber, a battery, an electrode within the combus- IOC Iof

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tion-chamber connected to battery, another electrode within said chamber normally disconnected from battery, and means for giving a step-by-step movement to said last-mentioned electrode to cause it to both make and break the circuit during each alternate movement only.

3. The combination of a combustion-chamber, a battery, an electrode within the combustion-chamber connected to battery, a toothed Wheel within the combustion -chamber normally disconnected from battery and adapted to engage said rst-mentioned electrode, a shaft to which said wheel is connected, another toothed wheel outside the combustion-chamber carried by said shaft and having a larger number of teeth than the wheel within the combustion-chamber, and devices engaging said outervvheel while the circuit is broken at the electrodes, and which causes the toothed electrode to both make and break the circuit during a single impulse.

4. The combination of a combustion-chamber, a grounded electrode therein, a toothed wheel within the combustion-chamber adapted to engage the grounded electrode, -a shaft to which said Wheel is connected, another toothed wheel outside the combustion-chamber carried by the shaft and having' a larger number of teeth than the wheel within thecombustionchamber, and means for actuating the outer wheel which is in engagement therewith while the circuit is being made and broken at the inner wheel, and which' separates therefrom While the circuit is broken at said inner wheel.

5. The combination of a combustion-chamber, a rotary toothed electrode therein, a toothed Wheel engaging said electrode, and means for operating said wheel.

6. The combination with a combustionchamber, of arotary toothed electrode therein, a toothed wheel engaging said rotary electrode, electrical connections for said wheel, and means for giving a step-by-step'movement to the star-wheel to cause its teeth to engage those of the said nist-mentioned electrode.

7 The combination with a combustionychamber, of a rotary toothed grounded elecgrounded electrode, electrical connections for bustion engines the combination with an igniter terminal or electrode and its insulation, of a rotary gas holder or cup adapted to retain inert products of combustion and thereby protect the insulation from deposition of carbon from subsequent explosions.

9. The combination of a combustion-cham: ber, an electrode therein, a shaft to which it is attached, insulating material surrounding the shaft, and a cup or bell carried by the shaft within the combustion chamber rotating therewith and surrounding such insulation.

10. The combination of the combustionchamber, an electrode within it, a shaft to which thev electrode is attached, insulating material surrounding the shaft, and a cup or bell closed at its end facing the combustionchamber and surrounding the insulation but open near the'wall of the combustion-chamber and having a space within it to receive and confine gases.

11. The combination of the combustionchamber, an electrode within it, a rotary shaft to which it is connected, and with which it revolves, a plug through which the shaft passes,

insulating material interposed between the shaft and the plug, and a cup or bell within the combustion chamber surrounding the shaftv and insulation, and which is closed at its end facing the combustion-chamber, but is open at its end close to a wall of the combustion-chamber.

l2. The combination of a combustion-chamber, an electrode within it, a shaft to which the electrode is secured, a plug through which the shaft passes, and which is formed with an inwardly-projecting sleeve, insulating material contained in the sleeve, and a cup or bell surrounding the sleeve, but leaving'a space around the sleeve within the bell to receive gases. A

13. The combination of a combustion-chamber, an electrode within it, a rod or shaft to which the electrode isl attached, insulating material interposed between the rod and the casing of the combustion-chamber, and a cup or bell secured to and rotating with said shaft and surrounding the insulating material, but leaving a space around the insulation toreceive gases.

14. The combination of the combustionchamber, an electrode therein, a rotary shaft to which the electrode is attached, a stationary frame or bracket against which the outer end of the shaft bears, and a spring for pressing the shaft outward against the bracket.

15. The combination of a combustion-chamloer, a toothed wheel therein, a shaft to which it isA secured, an outer toothed wheel, a pawl engaging therewith, an operating-lever for said pawl, and an adjustable block of insulating material to which said pawl is attachedand which is carried by said lever.

In testimony whereof have hereunto subscribed my name.

GEORGE J. MURDOCK.

Witnesses:

KATHARINE MACMAHON, A. M. PARKrNs.

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